1. Field of the Invention
This invention relates to a method of applying a tamper evident label to a package and an associated apparatus, and more specifically to a method and apparatus that facilitates placement of such a label on a precise location of a package.
2. Description of the Prior Art
The tampering with and adulteration of many commercially available products have become critical problems endangering health and destroying purity of many products. Many products which are adulterated or tampered with ultimately reach a consumer bearing no visible indication that such adulteration or tampering has occurred. Accordingly, it is highly desirable to provide a type of packaging which would give a reliable visual indication that there has been interference with the integrity of the product packaging.
My earlier U.S. patent application Ser. No. 07/209,822 filed June 22, 1988, the disclosure of which is expressly incorporated herein by reference, discloses a tamper resistant package and a method of making the same. An outer protective layer of an epoxide resin is placed on a package and is subsequently cured by ultraviolet radiation. This causes the outer layer to become extremely brittle such that any physical penetration of the outer layer will cause the outer layer to shatter. Such shattering will provide a clear visual indication that penetration of the protective layer has occurred as by cracking of the material and separation of the pieces from the package. The methods specifically disclosed for coating the package are (i) dipping the package in the coating material, (ii) spraying the package with the coating material or (iii) brushing the package with a brush or other means containing the coating material.
U.S. Pat. No. 2,131,774 discloses a closure including a sealing liner. A disc of fibrous material is placed between the closure and the sealing liner. When the closure is removed, the disc will rupture the closing liner. See also, U.S. Pat. Nos. 4,576,297 and 4,747,499.
It has been known to provide outer coatings which fracture responsive to operation of a tear strip. See U.S. Pat. No. 3,415,402. See also U.S. Pat. No. 4,479,585.
U.S. Pat. No. 2,074,490 discloses a tamperproof container having a composite consisting of a heat sensitive paint, printing ink and varnish. This composite is coated on the entire container.
U.S. Pat. No. 4,546,881 discloses an elastomeric material which protectively surrounds a container. The process of placing the material on the container involves providing a sheet of the material and placing both the sheet and the container in a vacuum mold. The package is then lowered into the mold and the sheet is tied around the package. Excess material is cut from the packaging material by blades.
In spite of these prior art teachings, there remains a need for an effective method and an associated apparatus for creating a tamper evident package having a coating material disposed on a precise location on a package. There remains a need for such a method and apparatus that can be employed on different shapes and sizes of packages.